Design and Validation of a Haptic Ankle Platform for Physical Human-Machine Interaction

摘要

The paper presents a new modular robotic ankle interface for physical human-robot physical interaction research. We describe the interface's mechanical design, control system, and its experimental validation. The experiments include the controller performance evaluation and haptic interaction trials with a human participant. The advantages of the presented interface include a modular design approach, portability, single-degree-of-freedom actuation, and adjustable ergonomic design. An impedance controller with an update rate of 10 kHz was implemented on a PC communicating with the motor controller using the CAN bus. Three tests were conducted to determine the system's performance. The first test measured the torque transmission capabilities of the platform, validating a gear-up transmission ratio of 20:1 from the theoretical design. The second test identifies the mechanical transfer function of the foot platform showing a cutoff frequency of 0.32 Hz. The third test checked the muscular activation of the Gastrocnemius Medialis and Tibialis Anterior muscles when walking on a virtual floor implemented on the platform. The peak muscular activation was compared to the output torque and angle of the system. Results showed a linear relationship between muscular activation and torque when in contact with the virtual floor. Future work includes controlling virtual jumping using a platform for each foot.